Two British Airways jets tested positive Wednesday for low-level radioactive contamination as the probe into the apparent murder of a former KGB agent uncovered a trail leading directly from London to Moscow.

FOX News has learned that British authorities are checking into whether anyone onboard the planes are associated with the radiation poisoning death of ex-Russian spy and Kremlin critic Alexander Litvinenko. ...

Litvinenko, who died Nov. 23 in a London hospital, claims Russian President Vladimir Putin was behind his death.

The former spy said he believed he had been poisoned on Nov. 1, while investigating the death of another Kremlin detractor investigative journalist Anna Politkovskaya. His hair fell out, his throat became swollen and his immune and nervous systems were severely damaged, he said.

Whether the Russian government is really behind the death of former KGB officer Alexander Litvinenko, 21st century Russia still looks like the kind of country that would assassinate its adversaries James Bond-style by slipping radioactive polonium-210 into their sushi.

After all, a former KGB spy holds the nation's highest office [President Vladimir Putin]. Former intelligence operatives are senior Cabinet members. The state controls virtually every media outlet. Many who, like Litvinenko, dare to criticize the government are intimidated, imprisoned or exiled. Some are murdered, their cases unsolved.

The Kremlin obstructs the work of international civil liberties watchdogs and silences domestic adversaries who criticize human rights abuses, particularly in the war-torn republic of Chechnya.

Given this record, it is not surprising that many people have been quick to pin the blame on the Kremlin, even though the Kremlin's many accusers have offered no evidence of its guilt, said Sarah Mendelson, an expert on Russia at the Center for Strategic and International Studies in Washington.